Using the BBraun BSmartTM Pressure Manometer to Prevent Unsafe Injection Pressures During Simulated Peripheral Nerve Blockade: A Pilot Study

Background: Peripheral nerve injury during regional anaesthesia may result from accidental intraneural placement of the needle, or forceful needle nerve contact. Intraneural injections are associated with increased resistance to injection, typically >15 psi. The BBraun BSmart™ is an inline mechanical manometer, offering a visual display of injection pressures. Objective: The primary objective of this study was to determine if using the BBraun BSmartTM manometer successfully prevents 90% of anaesthetists and anaesthetic assistants from injecting at pressures > 15 psi during simulated nerve block. Methods: This was a prospective observational study involving anaesthetists and anaesthetic assistants. Two 20 ml injections were performed by each participant, once when the BBraun BSmartTM manometer was obscured from view, and once with the manometer visible. A PendoTech PressureMATTMS recorded injection pressures. Results: 39 participants completed the study, with a total of 78 injections recorded. During the study, 32 peak pressures during the 78 procedures were recorded above the recommended upper limit of 15 psi, 41% of the total injections. The peak pressure rose above 15 psi in 24/39 (62%) injections when the BBraun Bsmart™ manometer was obscured, but only in 8/39 (21%) injections when the manometer was visible. Conclusion: The BBraun Bsmart™ manometer did not successfully prevent 90% of anaesthetists or anaesthetic assistants from injecting at unsafe pressures. However, using the BBraun BSmart™ did reduce the number of unsafe injection pressures generated by participants. When utilised in conjunction with PNS and ultrasound guidance, this may offer additional safety during peripheral nerve blockade.

Acute pain

This chapter discusses the management of acute pain. It begins with an introduction which describes the benefits of acute pain management and the measurement of pain. Analgesic drugs are then described, including paracetamol; non-steroidal anti-inflammatory drugs (NSAIDs), and opioids (including their comparative efficacy). Patient-controlled analgesia (PCA), epidural analgesia, and continuous peripheral nerve blockade are described. Transcutaneous electrical nerve stimulation (TENS) and acupuncture are discussed. The management of the patient with persistent pain and a substance misuse disorder is also discussed. The chapter concludes with a discussion of non-opioid adjuvant analgesics.

Use of Liposomal Bupivacaine in Pediatric Peripheral Nerve Blocks after Traumatic Amputation

Liposomal bupivacaine has been explored for indications in regional anesthesia, but little has been reported about its use in pediatric patients. In March 2021, the FDA approved an indication for liposomal bupivacaine as an infiltrated local anesthetic in children older than the age of six. Despite this recently expanded indication, the literature lacks reports of use for peripheral nerve blockade in children. We describe a case where liposomal bupivacaine was used for femoral and sciatic nerve blocks in a 5-year-old child with traumatic amputation of his lower leg. Pain control was excellent, with no pain or opioid use reported during the first 62 hours. After the regional anesthesia subsided, the patient required in total 4 oral doses of oxycodone 0.1 mg/kg prior to discharge. The patient did not develop chronic pain or phantom limb syndrome. While liposomal bupivacaine is not currently FDA-approved for peripheral nerve blockade in children, this case highlights a potentially effective use of this drug and possible area for further investigation.

Improvement of Superficial and Deep Cutaneous Microcirculation Due to Axillary Plexus Anesthesia Impaired by Smoking

Background: Understanding microvascular physiology is key to any reconstructive procedure. Current concepts in anesthesia increasingly involve regional peripheral nerve blockade during microvascular reconstructive procedures. Whereas favorable effects on perfusion due to these techniques have been reported earlier, little evidence focusing on its effects in most peripheral vascular compartments is available. Methods: A total of 30 patients who were to receive axillary plexus blockade (APB) were included. Microcirculatory assessment of the dependent extremity was conducted utilizing combined laser-Doppler flowmetry and white light spectroscopy. Two probes (1–2 and 7–8 mm penetration depth) were used to assess changes in microcirculation. Results: APB resulted in significant changes to both superficial and deep cutaneous microcirculation. Changes in blood flow were most prominent in superficial layers with a maximum increase of +617% compared to baseline values. Significantly lower values of +292% were observed in deep measurements. Consecutively, a significant enhancement in tissue oxygen saturation was observed. Further analysis revealed a significant impairment of perfusion characteristics due to reported nicotine consumption (max Bf: +936% vs. +176%). Conclusion: Cutaneous microcirculation is strongly affected by APB, with significant differences regarding microvascular anatomy and vascular physiology. Smoking significantly diminishes the elicited improvements in perfusion. Our findings could influence reconstructive strategies as well as dependent perioperative anesthetic management.

Peripheral Nerve Blockade and Botox Treatment in Chronic Migraine: A Comparative Study

Migraine is the most commonly encountered disabling headache. Chronic migraine significantly affects the quality of life and reduces the ability to attend work and social events, and consequently becomes an increasing economic burden.In recent years, peripheral nerve block with botulinum toxin A (botox) and local analgesics has been included in alternative treatment regimens.In cases of chronic migraine, botox is injected into the facial area, maxillary and mandibular nerve, and the head and neck muscles.Recent methods such as great occipital nerve (GON), and lesser occipital nerve, supra orbital nerve (SON), sphenopalatine ganglion blockade and trigeminal ganglion blockade have been applied using local analgesics. GON and SON blockade are the most frequently used of these methods. Studies related to these methods have shown a decrease in the frequency and severity of migraine pain.The results of this study showed that both GON and SON blockade and long-term application of BTX-A treatment were highly effective in the treatment of chronic migraine and both treatment methods had a similar level of effectiveness.That the follow-up period of this study was longer than in previous research can be considered a strong aspect of the study.

Pediatric Complex Regional Pain Syndrome: Stellate Ganglion and Lumbar Sympathetic Blocks

Complex regional pain syndrome (CRPS) is a chronic, localized pain condition following an injury, typically affecting a distal extremity. Although the pathophysiology of CRPS is unclear, multiple mechanisms are implicated, including peripheral and central sensitization as well as sympathetically mediated pain. Peripheral nerve blockade can treat the somatic component of CRPS pain, while sympathetic blockade may alleviate pain that is sympathetically mediated. Signs and symptoms manifest as abnormal sensory, motor, vasomotor, and sudomotor changes that are disproportionate to the inciting event. Early recognition of the signs and symptoms, followed by rapid implementation of a multidisciplinary treatment approach—including physical therapy, psychotherapy, pharmacotherapy, and sympathetic nerve blocks, is a major factor in improving outcome and preventing treatment-resistant CRPS.